ISO/IEC 17025:2017


  • Ovens
  • Freezers
  • Environmental enclosures
  • Oil and liquid baths
  • Thermometers
  • sensors
  • Temperature systems with meter/logger
  • Thermal chucks
  • Surfaces
  • Temperature wafers


“One Standard, one test, accepted everywhere.”

 ISO/IEC 17025 General requirements for the competence of testing and calibration laboratories is the main ISO standard used by testing and calibration laboratories. In most countries, ISO/IEC 17025 is the standard for which most labs must hold accreditation to be deemed technically competent.

ITS90 is the thermodynamic temperature scale that facilitates the comparability and compatibility of temperature measurements internationally. It specifies fourteen calibration points ranging from 0.65 K to 1357K.

A2LA is an acronym for American Association for Laboratory Accreditation. A2LA accreditation provides international credibility and compliance to organizations operating within dozens of industries. A2LA accreditation programs fulfill regulatory requirements and demonstrate competence and integrity to stakeholders.

Calibration is the documented comparison of the measurement device to be calibrated against a traceable reference device.

The reference standard may also be referred to as a “calibrator.” Logically, the reference is more accurate than the device to be calibrated. The reference device should also be calibrated traceably.

When you make calibration and compare two devices, you may find out there is some difference between the two. So, it is pretty logical that you may want to adjust the device under measure correctly. The process is often called adjustment or trimming.

Formally, Calibration does not include adjustment but is a separate process.

Traceability refers to the value of a standard where it can be related to stated references (national or international standards) through an unbroken chain of comparisons, all having stated uncertainties

The uncertainty of measurements can come from various sources such as the reference measurement device used to make the measurement, environmental conditions, the operator making the measurements, the procedure, and many other sources.

Shortly and, we can say that it is the “doubt” of the measurement, telling us how good it is. Every measurement we make has some “doubt,” and we should know how much this “doubt” is to decide if the measurement is good enough for the usage.

The PT100 sensors embedded Wafer finds application in semiconductor processing equipment where knowing and controlling the temperature of the surface of a chuck or wafer is of interest. Precisely calibrated thin-film sensors are used  on the 300/200 mm wafer in several points to determine the overall surface temperature of the wafer and/or prober chuck system, ultimately to evaluate measurement uniformity and uncertainties.

Sigma Sensors is an “ILAC MRA – American Association for Laboratory Accreditation” ISO17025 accredited laboratory specializing in 300/200 mm Wafer, Chuck system calibration in the semiconductor industry. Sigma Sensors is the only one that has validated the thermal calibration method for the wafer/chuck system. We can evaluate and determine the expanded uncertainty for wafer itself calibration, where other wafer testing companies can only measure single sensor calibration uncertainty.